Is biomass and feeding selectivity of nematodes related to depth?

Type:

Master Thesis subject (30 ECTS)

programme:

EMBC+

Nematodes constitute the most abundant metazoan taxon in deep-sea sediments, even surpassing larger size groups at depths below 3000 m, such as macrofauna and demersal fish, in terms of total biomass per surface. The nematode success in terms of standing stock is difficult to relate to their diet in the deep sea, which is assumed to be poorly diversified and of low quality, depending mainly on the surface primary production.
To try to understand patterns in nematode biomass, trophic structure and how local environment can affect their distribution we will use field sampling to get insight in the true nematode species biomass and feeding selectivity (trophic diversity), together with their functional role in ecosystem function. The hypotheses investigated are: (1) a higher biomass is linked to a higher trophic diversity and (2) local environmental conditions shape the nematode community structure.
The study will be conducted along the European margin and will comprise depths zones of ~500 m and 1000 m. Samples collected with a Multicorer will be processed and the nematodes extracted for biomass and ecological analyses. Environmental analyses will be performed to support ecological evidences.